This invention relates to a device for shooting image of a document, an object or the like. More particularly, it relates to a device for image-shooting both sides of a document, such as an instrument. In a further aspect, this invention relates to a method for image-shooting a moving document, such as an instrument, more particularly, to a method for high-speed image-shooting both surfaces of a descending document.
As a device for simultaneously photographing both sides of a document, the JP Patent Kokai Publication JP-A-No.60-154243 shows a device having a silver salt film and a slit camera, as shown herein in FIG. 5.
Referring to FIG. 5, the device shown in the JP Patent Kokai Publication JP-A-No.60-154243 has a transporting channel for the document made up of a pair of upper transporting rolls 1A, 1B, a pair of lower transporting rolls 2A, 2B and a pair of cover glass plates 3A, 3B arranged between these transporting rolls. The front and reverse side images of the document travelling through a space between the cover glass plates 3A, 3B are captured on a silver salt film by a slit camera, not shown, via reflecting mirrors 4A, 4B, respectively.
With the above device, since the document is held by at least one of the upper transporting rolls 1A, 1B or the lower transporting rolls 2A, 2B, the photographing means that can be used is necessarily limited to that employing a slit camera.
According to the keen investigation of the inventors, the following drawbacks have been revealed in the related art.
However, the device for simultaneously photographing both surfaces of the document with the aid of the slit camera as proposed in the JP Patent Kokai Publication JP-A-No.60-154243 suffers from a problem that a liquid needs to be employed for developing a silver salt film. Consequently, a demand has been raised for an electronic type (i.e. dry type) device for simultaneously photographing both surfaces of the document. Although a device for simultaneously photographing both sides of the document with the aid of line sensors has also been proposed, the document transporting speed needs to be substantially one-half that of the conventional device, due to constraint imposed by processing time for the line sensors, as a result of which it has not been possible to further expedite the image-pickup process.
In addition, since the line sensor is employed as an image-pickup means in place of photographing means, the document needs to be transported at a speed correctly synchronized with the line sensor readout speed, whereby limitations are further placed on the image-pickup speed.
In a further aspect, there is a conventional photographing system for a document, such as instrument (referred to hereinafter as xe2x80x9cinstrumentxe2x80x9d), wherein the contents of the instrument are captured (recorded) by holding an end part of the instrument, transporting the instrument at a velocity sufficient to preclude capturing errors and by photographing the contents of the instruments.
However, with the above conventional instrument photographing system, in which a silver salt film is developed, it is necessary to perform disposal of waste liquid. In addition, the photographing is carried out consecutively without regard to whether or not an object to be image-shot (instrument) is positioned in a line image-shooting range, thus raising the cost. On the other hand, in a system using the line sensor, transport of the instrument and image-shooting by the line sensor need to be fully synchronized with each other, resulting in difficulty in high-speed image-shooting.
Generally, it is a basic objective of the present invention to provide a novel device for taking image (or picture) of any surface of a document (or any equivalent object) at a high speed under the condition that image can be further processed and/or stored for various needs.
Specifically it is an objective of the present invention to provide a novel device for taking image (or picture) of both surfaces of a document whereby both surfaces of the document can be image-taken at a high speed by electronic means.
It is another objective of the present invention to provide a novel device for taking image of both surfaces of a document whereby both surfaces of the document can be image-taken at a high speed without necessitating a document transporting unit configured for controlling the document feed rate highly accurately.
It is a further objective of the present invention to provide a novel device for simultaneously taking image of both surfaces of a document at a high speed.
In a further (fourth) aspect, it is an objective of the present invention to provide a method (or device) for image-shooting a document whereby picture dropout may be prohibited and a high-quality image may reliably be obtained, even under a high speed image-shooting.
Still further objectives of the present invention will become apparant in the entire disclosure including claims.
According to a general aspect, an image, i.e., two-dimensional image (or picture) can be taken at a high speed on any surface of a moving target matter, typically a document during its quick movement (typically descending movement) at a high speed by image-shooting two-dimensionally any surface of the moving target matter, in which the two-dimensional image-taking is carried out likewise xe2x80x9cphotographingxe2x80x9d, typically strobo-photographing but without recourse to a photosensitive film using photosensitive salts, generally termed as xe2x80x9cphotographic filmxe2x80x9d. The two-dimensional image-taking is carried out under the condition that the image can be generally converted to image signals. Such signals can be directly processed, stored, recorded or further processed without giving rise to the photographic developing process. The two-dimensional image-taking is typically termed as xe2x80x9cimage-shootingxe2x80x9d in the present invention for convenience of illustration, and the image-shooting may be carried out typically using a video camera system.
The two-dimensional image-shooting which is useful in the present invention typically includes an area sensor, e.g. CCD array of a two-dimensional array, but not limited threrto, and generally can be a photo-electronic sensor array capable of the two-dimensional image-shooting. It should be noted, any equivalent means to such CCD array may be further employed according to the present invention as long as the requirements are satisfied.
Typically, a device for image-shooting documents comprises a first (or upper) transport system which feeds documents toward downstream to freely descend by a given number by number of the documents, and an image-shooting system disposed downstream of said upper transport system and adapted to image-shoot at least one surface (or both surfaces) of the descending document.
According to the present invention, various aspects and embodiments are accomplished based on the basic concept.
According to a fourth aspect, the picture drop out at a high speed image-shooting may be eliminated by adjusting the image-shooting timing so that image-shooting will occur at all times when an object to be image-shot is within the image-shooting range.
That is, the fourth aspect of the present invention provides a method for image-shooting a document including means for transporting and causing descent of a document, such as an instrument, a sensor for detecting the document in descent for outputting a detection signal, and an area sensor for image-shooting the document in descent responsive to the detection signal. An image-shooing timing is generated from the detection signal, the area sensor image-shooing the document in accordance with the image-shooting timing.
According to the fourth aspect, the time which elapses as from the time of end of detection of the document until image-shooting is fixed by detecting the descending document and detecting the size of the document along the direction of descent from the duration of detection. Alternatively, the document may be reliably image-shot during descent of the document within the image-shooting range of the area sensor by image-shooting the document in descent after lapse of a pre-set time as from detection of the leading end or the trailing end of the document along the direction of descent of the document. In either cases, picture dropout is prevented from occurring.
According to one aspect of the present invention there is provided a device for image-shooting both surfaces of a document having a first transport system for allowing plural documents to descend by a pre-set number and image-shooting system for two-dimensionally image-shooting both sides of a document(s) fed from the first transport system arranged downstream of said upper transporting system. It should be noted that the term xe2x80x9cdocumentxe2x80x9d represents whatever object of which an image is to be taken in the present invention, generally having a shape of a sheet. The first transport system usually comprises an upper transport system.
In the first aspect, the documents are usually fed from an upper transport system to an image-shooting area. The feeding may be done, e.g., by allowing the documents to freely descend to the image-shooting area or under a controlled speed, as well as in a vertical horizontal direction, or in a tilted or slanted direction.
The image-shooting system comprises two-dimensional image-shooting means such as so-called area sensor or the like which is capable image-shooting the document at least in an areal unit of certain practically useful dimensions, rather than in a linear unit. The image-shooting may be conducted either simultaneouly or alternately in sequence. Also an entire surface or a certain divided part of a document may be shot by one shooting.
In the image-shooting area of the image-shooting system, the document must travel so as not to disturb (shield) essential part of the document containing important information. Such travelling may be, in general, carried out by free descending (falling down) or tranporting the document by any means for controlling the travel (speed) of the document.
According to the first aspect, the freely descending document is image-shot in two-dimensional fashion at once, which eliminates any transport system of document having an exact transport speed as well as eliminates the need for retaining or constraining the document.
Therefore, the desired document transport and image-shooting both at a high speed is accomplished. A preferred variant provides the free-descending of documents in the image-shooting area, which can eliminate any document transport mechanism and is freed of any possible inclusion of such mechanism in a picked-up image.
According to a further variant, provision of a document travel control means which controls the travel of the document fed from the first (upper) transport system within the image-shooting area, timing of shooting is easily matched with the position of the document. In a further variant, the document travel control means transport the document supporting the document, which can provide a right and accurate positioning of the document opposing to the image-shooting system, e.g., at right angles to the axis of the system.
According to a second aspect of the present invention, simultaneous image-shooting is effected on both the sides of a document using two-dimensional image-shooting means such as area sensor etc. Upon shooting, both the surfaces (front and reverse) should be positioned entirely right in the image-shooting area without being shielded or failure. For this purpose, the documents are fed sheet by sheet from the upper transport system, in which the fed document is allowed to freely descend within a space formed between a pair transparent vertical guide members for free descending to reach the image-shooting area, upon which both the entire surfaces of the document are shot at the same time.
In this aspect, there is no need for a specific document transport system which would require a defined precise feed speed, nor a need for retaining the document during the transport or image-shooting, and thus a high speed is achieved for image-shooting of the document.
In the first and second aspects, it is preferred that a pair of light emitting apparatus (or illuminating apparatus) are provided which emit light in response to a detection signal of a sensor for detecting the document position, and a pair of image-shooting system for image-shooting both sides of the document in response to the detection signal of the sensor. The light emitting apparatus are disposed opposing to the document and emit light against both the surfaces of the document just positioned at the image-shooting area. In this manner, both the surfaces of the freely descending document is image-shot at a high speed, yet more, with a high quality without missing part of an image. It is also possible to further store or record the shot-image using, e.g., an area CCD camera as the image-shooting system.
According to a third aspect, there is provided a device for image-shooting both sides of documents, which is mentioned herein as one typical embodiment according to the general aspect, provided that both the surfaces of the document can be image-shot simultaneouly. This aspect provides image-shooting at a high speed, too.
Embodiments according to the fourth aspect will be disclosed at the end of the DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS.
In the following meritorious effects of the present invention will be summarized.
According to the present invention, both surfaces of the document may be image-shot using two-dimensional image-shooting system at a high speed, particularly also at the same time. In particular, if a camera employing image-pickup elements, such as area sensors, is employed, it becomes possible to eliminate film developing operations and to expedite the document image-shooting process.
It is preferred to provide a detection sensor for detecting the documents at a position between the upper transport system and the image-shooting system, thereby obtaining a timing for image-shooting, which leads to avoid occurrence of missing part of an image or mixed shot of plural images.
The picture data taken using an area sensor such as a CCD camera may also be magnetically, optomagnetically or optically recorded for facilitating picture editing or retrieval.
Also, the provision of the detection sensor of the document""s position provides timing for light emission and image-shooting as well as an optimum illumination to the document just positioned at the image-shooting area.
In addition, by providing two-dimensional image-shooting means, such as an area sensor, it becomes possible to image-shoot the entire surfaces of the document at a time.
According to a preferred embodiment to provide detection of jamming of documents for stopping the operation of the upper transport system, there is no risk to get mixed pictures of documents.
Furthermore, since it is possible to eliminate holding the document according to free descending of the document, an illuminating device and an image-shooting device may be provided facing the object, there is no risk of the holding means being captured in a shot image of the object, so that both surfaces of the document descending at a higher velocity may be image-shot simultaneously.
It is possible to provide the transport control means of the documents within the image-shooting area, easier matching of the shooting timing with the document position. Also right positioning of documents against the image-shooting is possible by the transport control means.
It is preferred each of a pair of the transport control means and the image-shooting means are provided at upstream and downstream respectively, which enables alternate image-shooting each side of the document at right positioning as well as prevention of capturing redundant members in the picture.
It is possible to use blown air to transport the document, particularly in a slanted guide members, which eliminates particular transport mechanism.
Other advantages will become apparent from the entire disclosure.
Preferably, the taken image data are recorded magnetically, opto-magnetically or optically for eliminating the problem of disposal of waste liquid produced with the use of silver salt films thus significantly saving the labor in picture editing and retrieval.
By providing guide members for guiding the document freely descending, the descending document may be positively guided to the image-shooting area without being affected by the wind produced by e.g., a cooling fan provided in the device. Also preferably, the guide members are transparent.